getfsstat / nullsfs / automount bug?

There appears to be a bug in the system call related to getmntinfo(3) / getfsstat(2)
, when if the "automount" flag is set on "nullfs" mounts, it is not returned on
a getfsstat "WAIT" call. The non-refreshed, non-blocking "MNT_NOWAIT" produces the
correct result.

I first noticed this when debugging why my nullfs autofs partitions weren't being
automatically unmounted. (FreeBSD current and release)

The somewhat hacked snippet from automount.c in the example below demonstrates this -
When called with no parameters, it performs a MNT_WAIT request, otherwise a MNT_NOWAIT
request is performed:

Cheers, Jamie

 | #include <stdio.h>
 | #include <string.h>
 | #include <sys/mount.h>
 |
 | int main(int argc, char **argv)
 | {
 | 	struct statfs *mntbuf;
 | 	int i, nitems;
 |
 | 	nitems = getmntinfo(&mntbuf, (argc == 1) ? MNT_WAIT : MNT_NOWAIT);
 | 	if (nitems <= 0)
 | 		printf ("getmntinfo fail\n");
 |
 | 	for (i = 0; i < nitems; i++) {
 | 		if (strcmp(mntbuf[i].f_fstypename, "autofs") == 0) {
 | 			printf("skipping %s, filesystem type is autofs\n",
 | 			    mntbuf[i].f_mntonname);
 | 			continue;
 | 		}
 |
 | 		if ((mntbuf[i].f_flags & MNT_AUTOMOUNTED) == 0) {
 | 			printf("skipping %s, not automounted\n",
 | 			    mntbuf[i].f_mntonname);
 | 			continue;
 | 		}
 |
 | 		printf("%s IS automounted!!!!!!!!!\n",
 | 		    mntbuf[i].f_mntonname);
 | 	}
 | }

 | 14:24 [2] (1) "autofs" root_at_thompson# df
 | Filesystem        1K-blocks     Used      Avail Capacity  Mounted on
 | /dev/ada1p2         5061628   707264    3949436    15%    /
 | devfs                     1        1          0   100%    /dev
 | /dev/ada1p4         5061628   535004    4121696    11%    /var
 | /dev/ada1p5       978973296 21689416  878966020     2%    /usr
 |
 | 14:24 [2] (2) "autofs" root_at_thompson# mount
 | /dev/ada1p2 on / (ufs, local)
 | devfs on /dev (devfs, local, multilabel)
 | /dev/ada1p4 on /var (ufs, local, soft-updates)
 | /dev/ada1p5 on /usr (ufs, local, soft-updates)
 |
 | 14:25 [2] (3) "autofs" root_at_thompson# mkdir /tmp/automounted /tmp/manual
 |
 | 14:25 [2] (4) "autofs" root_at_thompson# mount -t nullfs -o ro /usr/src /tmp/manual
 |
 | 14:25 [2] (5) "autofs" root_at_thompson# mount -t nullfs -o ro,automounted /usr/src /tmp/automounted/
 |
 | 14:26 [2] (6) "autofs" root_at_thompson# df
 | Filesystem        1K-blocks     Used      Avail Capacity  Mounted on
 | /dev/ada1p2         5061628   707264    3949436    15%    /
 | devfs                     1        1          0   100%    /dev
 | /dev/ada1p4         5061628   535004    4121696    11%    /var
 | /dev/ada1p5       978973296 21689420  878966016     2%    /usr
 | /usr/src          978973296 21689420  878966016     2%    /tmp/manual
 | /usr/src          978973296 21689420  878966016     2%    /tmp/automounted
 |
 | 14:26 [2] (7) "autofs" root_at_thompson# mount
 | /dev/ada1p2 on / (ufs, local)
 | devfs on /dev (devfs, local, multilabel)
 | /dev/ada1p4 on /var (ufs, local, soft-updates)
 | /dev/ada1p5 on /usr (ufs, local, soft-updates)
 | /usr/src on /tmp/manual (nullfs, local, read-only)
 | /usr/src on /tmp/automounted (nullfs, local, read-only, automounted)
 |
 | 14:26 [2] (8) "autofs" root_at_thompson# ./a.out
 | skipping /, not automounted
 | skipping /dev, not automounted
 | skipping /var, not automounted
 | skipping /usr, not automounted
 | skipping /tmp/manual, not automounted
 | skipping /tmp/automounted, not automounted
 |
 | 14:26 [2] (9) "autofs" root_at_thompson# ./a.out x
 | skipping /, not automounted
 | skipping /dev, not automounted
 | skipping /var, not automounted
 | skipping /usr, not automounted
 | skipping /tmp/manual, not automounted
 | /tmp/automounted IS automounted!!!!!!!!!